"The paper focuses on the preconditions, contends, and impacts of environmentally-oriented innovations in local transport policy. In spite of the ongoing deterioration of traffic-related environmental problems in European cities, urban transport policy seemed to be extremely resistant to fundamental environmentally-oriented changes. We assume that the main obstacles for achieving an environmentally sustainable transport policy are not lacking knowledge (transport concepts) in the first place, but political will and skill (transport politics). In the 'critical' literature on urban transport policy some cities are discussed as being forerunners, because they are much more successful than most others in implementing 'green' transport policies over longer periods of time. Some of these 'relatively successful cities' are Amsterdam and Groningen (NL), Zurich (CH), and Freiburg (D), which were chosen for case study. It is investigated, how changes in transport policies evolved (Policy-Input), how 'green' the environmentally-oriented urban transport policies really are (Policy-Output), and whether these changes make a difference in terms of reducing car use and improving environmental conditions in these cities (Policy-Impact). A model of transport policy innovations will be outlined, which should enable to systematise the political processes of change of urban transport policy. It assumes, that basic policies changes evolve in three phases, in which different factors and conditions are of special relevance. The study concludes, that fundamental environmentally-oriented policy changes are difficult and requiring, but - on principle - possible. Local governments in Switzerland, the Netherlands and Germany could decide, whether to implement growth-oriented or environmentally-oriented strategies in transport policies. Consequently, local governments are able to influence urban transport trends to a remarkable degree even within the existing framework conditions." (author's abstract)